The SBIR Fast-track develops, tests, and commercializes the ?Active Disposable Cap for Endoscope (ACE) Tip Stabilization and Complete Visualization and Dissection of Serrated Sessile Polyps.? The disposable system includes a distal-connecting cap, allowing a clinician to manipulate tissue and perform targeted aspiration during complex polypectomies using proximal controls, without occupying the endoscopic working channel. Public Health Problem: In the U.S., colorectal cancer is one of the most deadly and costly forms of cancer. Current endoscopy tools are inadequate to consistently enable full resection of colon polyps. Even polyps <10 mm have an estimated 29% incomplete resection rate. Larger (>2cm), complicated polyps (e.g., flat sessile lesions) are particularly prone to recurrence and malignancy, impacting patient care and healthcare costs. Rates of standard piecemeal resection, which is significantly associated with residual polyp, increases from 3% at <2cm to 85% for polyps >2cm. Endoscopic submucosal dissection (ESD) enabled en bloc removal of >2 cm polyps in 84-95% of cases, and showed a 0-2% tumor recurrence, in one Japanese study, though this expertise is limited outside this geographic region. In nearly all other countries, rates of en bloc ESD are well below 50% - and ESD procedures take over 100 minutes compared to 20-50 minutes for piecemeal resection. Open surgical resection further increases risks and costs. The goal of this proposed project is allowing a safe and effective en bloc ESD with full lesion removal to be performed rapidly. Phase I Hypothesis. ACE enables en bloc resection of large simulated polyps and acceptable forces on tissues in vitro, and demonstrates improved working capabilities in vivo with any damage to porcine colon limited to the mucosa. Aim 1 ? ACE demonstrates improved polypectomy functionality and demonstrates safety from perforation in bench models. Acceptance Criteria: Favorable clinician response on ACE capabilities and performance based on 10-point Likert scale, and ?75% (18/24) successful en bloc resections of ? 2cm, difficult lesions in vitro. Aim 2 ? Confirm safety and efficacy feasibility of ACE in pilot preclinical study. Acceptance Criteria: Pilot in vivo study (N=3) successfully achieves simulated ?2cm polyp removal en bloc in porcine model with no significant colon damage or adverse events at up to 72-hours post-procedure. Phase II Hypothesis. ACE is safe and effective for improving endoscopic access and stability, and complete lesion removal, during complex polypectomies in the colon. Aim 3 ? Verification and validation to support regulatory submissions. Acceptance Criteria: Pass acceptance criteria on each individual test. Acceptance criteria are set on an individual test basis using a risk- based approach. Aim 4 ? Demonstrate faster en bloc resection and same or better safety with ACE versus endoscope-only. Submission of the De Novo premarket application to the FDA. Acceptance Criteria: ACE reduces en bloc resection procedure time relative to endoscope-only resection (N=16; p<0.05, ?<0.1) with the same or less visual and histological mucosal damage and no adverse events. FDA De Novo submission.